The woolly mammoth has been having a terrible time of it. Not only did this fantastically furry beast go extinct some 4,000 years ago, but now increasing numbers of influential people are saying that we should not try to bring it – and other extinct species – back to life, as scientists and an assortment of tech-savvy dreamers have recently proposed to do.

I’m talking about resurrection biology, aka de-extinction, the idea that scientists could use new genetic technologies like cloning to resurrect extinct animals using DNA extracted from museum specimens, frozen tissue samples or even (in the case of the mammoth) from carcasses preserved under the Arctic tundra.

The latest censure of resurrection biology comes from the usually sober Scientific American. Last week’s editorial argues that “with limited intellectual bandwidth and financial resources to go around, de-extinction threatens to divert attention from the modern biodiversity crisis.” The IUCN Red List categorises more than 20,000 species as threatened with extinction, Sci Am reminds us, and with a looming mass extinction of this size, “conservationists face difficult choices about which species and ecosystems to try to save, since they cannot hope to rescue them all.”

“Against this backdrop, a costly and flamboyant project to resuscitate extinct flora and fauna in the name of conservation looks irresponsible: Should we resurrect the mammoth only to let elephants go under? Of course not.”

The editors warn that “the revival of a single extinct beast in a lab does not mark the return of a species, and creating viable populations of extinct animals that could flourish in modern ecosystems is a far more difficult challenge”, although they do concede that the de-extinction enterprise is not completely without merit. Its technologies, they say, could be used to help endangered species that have lost much of their genetic diversity “such as the black-footed ferret and the northern white rhino. Such investigations, however, should be conducted under the mantle of preserving modern biodiversity rather than conjuring extinct species from the grave.”

In short, their argument is that de-extinction is too expensive and we should spend our brainpower and cash on extant species, not extinct ones. (And not be flamboyant if we can help it.)

I found it interesting that Scientific American mentioned the northern white rhinoceros, perhaps better called by an earlier name, Nile rhinoceros. It’s ridiculously close to being extinct. In 1960, there were probably over 2,000 in northeast Africa. Today, thanks to relentless poaching and weak conservation efforts, there are none known to be left in the wild and a mere seven in captivity, of which only four, two males and two females, are still young enough to breed.

The Nile rhino is hanging on by the very tip of its insanely overpriced horn. Some biologists would call it a ‘zombie species‘, not technically extinct but doomed to oblivion because of its tiny, inbred population.

The two females are mother and daughter, and the males are also close relatives. Only one, the older male, has ever known life in the wild; the other three were born in a Czech zoo. All four breeding-age animals are now at Ol Pejeta Conservancy in Kenya, where I visited them in 2011, and where conservationists are still trying to persuade them to reproduce.

Due to the last members of the species being adapted to zoo life, it might also have permanently lost memory of important natural behaviours, the things adult animals teach their young to help them to survive. It is certainly functionally extinct, i.e., no longer performing its role in the ecosystem. Large parts of the Nile rhino’s historic range in northeast Congo and South Sudan are also bedeviled by rampant poaching and armed conflict.

In other words, the remnant micro-population of Nile rhino is rather like a beginning-stage population of de-extincted mammoths or another large mammal would be: missing important behaviours, likely with limited genetic diversity (because they’d have been derived from a small amount of genetic material) and most definitely functionally extinct, with its place in the ecosystem perhaps unsure due to changes that might have occurred in its absence.

I’m not sure why the Scientific American editors endorse new genetic technologies to build the Nile rhinoceros population but argue against using very similar technologies to bring back other species like the thylacine and the passenger pigeon, species that humans have pushed into extinction within the last century and which could have important roles to play in our ecosystems if brought back.

Most of us have been taught that there’s an abrupt line between being extant and being extinct, whereas there is and always has been something of a continuum between the two states. Resurrection biology makes the continuum between species that are abundant, species that are extremely rare and species that have no living members more obvious than it has been in the past because there’s now potential to reverse away from ‘total’ extinction back along the continuum to ‘thriving’. This apparently makes many people, including some serious science editor types, irrationally uncomfortable.

Candidates for de-extinction: Three extinct North American birds (l to r) Ivory-billed Woodpecker, Carolina Parakeet, Passenger Pigeon, in the collection of the Field Museum of Natural History, Chicago.